Duolingo vs OttoLearn
| Duolingo | OttoLearn | |
|---|---|---|
| Free plan | Yes | No |
| Free trial | Yes | No |
| Paid from | Free | — |
| Open source | No | No |
| Platforms | Android, iOS, macOS, Web | Web, iOS, Android |
| Free plan | Yes | No |
Both are listed in Best Learning Gamification Software. On Samsung Mobile US Press, Duolingo scores higher on our published basis.